Universal implant

ABSTRACT

A dental implant anchor for attaching an abutment with at least one replacement tooth to the jaw bone of a mammal has a lower portion with an outer tapered surface which has a thread and is textured to improve bone integration to the anchor. The anchor also has an upper portion with a polished collar, the upper portion having an upper surface adapted to be engaged by the abutment. The anchor has an abutment receiving bore extending into the anchor and opening at the upper surface of the upper portion for receiving an abutment, and a threaded bore portion extending into the anchor, below the abutment receiving bore for receiving a screw.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of application Ser. No. 10/122,988 filed Apr. 15,2002 and now U.S. Pat. No. 6,733,292.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates generally to the field of dentistry, andin particular, to a new and useful universal implant arrangementincluding a tapered and threaded anchor for implantation into the jawbone of a mammal, means for rotating the anchor for seating it in thejaw bone, and means for mounting a replacement tooth or teeth to theanchor.

For the purpose of this disclosure and the claims forming a partthereof, relative terms and terms having functionally opposite butequivalent meanings such as, but not limited to, up, down, left, right,upwardly, downwardly, male and female, are used to include theiropposite meaning. For, example, when referring to an implant anchorhaving a lower body portion with an upwardly facing opening, this ismeant to also include an implant anchor having an upper body portionwith a downwardly facing opening.

A wide variety of dental implant structures and systems is known.

U.S. Pat. No. 4,960,381 to Niznick, for example, discloses a screw-typedental implant anchor with an externally-threaded body portion joined toa top portion having an unthreaded exterior wall, and an internal,wrench-engaging surface.

U.S. Pat. No. 4,411,624 to Ogino, et al. discloses a dental implant witha dental root part having a substantial portion of the dental rootsurface to be placed in contact with the jaw bone, formed of abiologically active glass or glass-ceramic material that is contoured tohave a selected taper.

U.S. Pat. No. 4,758,160 to Ismail discloses a dental implant having analveolar surface and a hollow core therein, a prosthetic head having ashaft thereon, and a prosthesis. The shaft has a particular structure.

U.S. Pat. No. 4,863,383 to Grafelmann teaches a self-tapping screwimplant.

U.S. Pat. No. 5,417,570 to Zuest, et al., U.S. Pat. No. 5,651,675 toSinger, U.S. Pat. No. 6,050,819 to Robinson and U.S. Pat. No. 6,126,662to Carmichael et al., all disclose the use of the so called Morse taperin a dental implant.

U.S. Pat. No. 5,437,551 to Chalifoux teaches a dental system forinsertion into a bore of a jaw bone of a patient which comprises animplant having a central bore extending from a top surface through aportion of the vertical height of the implant, one first extensionextending from and directly attached to a first wall of the centralbore, a dental post having a stem section shaped to fit into the centralbore and having a second wall with at least one second extensionattached directly to the post and positioned to frictionally fit withthe first extension to retain the post within the central bore.

U.S. Pat. No. 5,199,873 discloses an implant with a stepped and threadedbody for extending into the jaw bone.

Despite the effort of many practitioners in this field, a need remainsfor an effective universal dental implant arrangement.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a universal implantarrangement which includes an implant anchor, a platform or body thatcan be used, for example, for rotating the anchor to fix it in a jawbone hole (and acts as an attachment surface for an external attachmentabutment), and an abutment for mounting at least one tooth replacement,such as a crown or cap, to the anchor.

One of the main objects of the present invention is to provide a trulyuniversal implant including both internal attachment and externalattachment possibilities. This is achieved by utilizing an anchor havingan internal void (also referred to here as a abutment receiving bore)adapted for internal attachment-type abutments, along with a (anattached) platform that can be used for various purposes. Theuniversality of the implant is in providing the alternative of leavingthe platform in place, causing the implant to function as an externalattachment implant, or removing the platform and thereby converting theimplant into an internal attachment implant. The platform can support anexternal attachment abutment or be remove so that the implant canaccommodate an internal attachment abutment. For the purpose thisdisclosure the term “abutment” can mean any one or more of a widevariety of dental superstructures, such as a crown, a clip bar or sparkerosion bar (that can be attached to more than one implant), a stud orpost for helping support an over-denture, or the like. The externalabutment can be attached to the platform, the platform thus providingany foundation needed for connecting the external abutment to theanchor.

Accordingly, another object of the invention is to provide a dentalimplant arrangement for attaching a replacement tooth to the jaw bone ofa mammal, which has an anchor for implantation into the jaw bone. Theanchor has a lower outer tapered surface and a thread in a preferredembodiment, although anchors without a thread and even without a taperedsurface, may also be used. The anchor also has an upper portion with anupper surface and an abutment receiving bore extending into the anchor.A platform is attached to the upper surface of the anchor also forrotating the anchor in the jaw bone, when rotation is needed to installthe anchor. A non-circular projection projects from and is part of thetop of the platform. This can be used for engagement by a wrench forrotating the platform. Orientation structures such as co-rotation keysand/or a Morse taper, can also transmit rotation of the platform to theanchor. The orientation structures can also be used to orient anabutment to the correct rotational position with respect to the anchor.The abutment for supporting the tooth replacement may have a foundationextending into and fixed to the abutment receiving bore in the anchorwhen the tooth replacement is to be supported on the anchor as aninternal attachment. The platform may serve as a permanent part of theimplant arrangement in that it forms the attachment location for thecrown, or for hardware that supports the crown. The platform also servesas part of the installation process, for example, to rotate a threadedanchor into the jaw bone, and ultimately may be removed and replacedwith an internal attachment abutment or other internal attachmentstructures.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference is made to the accompanying drawings and descriptive matter inwhich a preferred embodiment of the invention is illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a side elevation of a first embodiment of the invention;

FIG. 2 is a sectional view taken along lines 2—2 of FIG. 1;

FIG. 3 is an exploded view of the embodiment of FIGS. 1 and 2;

FIG. 4 is an exploded view of another embodiment that is similar to thatof FIGS. 1 and 2;

FIG. 5 is an exploded view of a still further embodiment of theinvention;

FIG. 6 is an exploded view of another embodiment of the invention;

FIG. 7 is an exploded view of a still other embodiment of the invention;

FIG. 8 is an exploded view of another embodiment of the invention;

FIG. 9 is an elevation, partly in section of another embodiment;

FIG. 10 is a partial perspective and exploded view of the platform andtop of the anchor of another embodiment of the invention;

FIG. 11 is a partial perspective view of another embodiment;

FIG. 12 is a view like FIG. 11 but of another embodiment of theinvention;

FIG. 13 is an exploded view of the embodiment of FIG. 8 showing a crownor cap used as a tooth replacement;

FIG. 14 is a view similar to FIG. 13 of the embodiment of FIG. 6 with atooth replacement; and

FIG. 15 is a view similar to FIG. 11 of another embodiment of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, in which like reference numerals are usedto refer to the same or similar elements, FIG. 1 illustrates a dentalimplant arrangement for attaching at least one replacement tooth to thejaw bone of a mammal.

The arrangement comprising an anchor 10 for implantation into a hole inthe jaw bone, the anchor having a lower portion 12 with an outer taperedsurface 14 and a thread 16 on the outer tapered surface. Thread 16 mayor may not be present on surface 14. The anchor has an upper portion 18with an upper or upwardly facing surface 20 and an abutment receivingbore 22 shown in FIG. 2, extending into the anchor and opening at theupper surface 20. Texturing or roughening of the surface 14 and/orthread 16 is accomplished, for example, by acid etching, plasma spray oftitanium or blasting.

A platform 24 is attached onto the upper surface 20 of the anchor 10 forrotating the anchor in the jaw bone hole. A non-circular projection 26is fixed to and formed as one piece with a top surface 28 of theplatform 24 and has at least one external wrench-engaging surfaceadapted for engagement by a wrench for rotating the platform andcontiguous anchor thereby seating the anchor in the jaw bone. Projection26, is made as one piece with the rest of the platform 24, e.g. ofbiocompatible metal. The wrench-engaging surface may be a hexagonal nutstructure as shown, any other polygon or any other non-circular shapesuch as an oval so that a wrench can be used to turn the platform 24.

Orientation or co-rotation means are defined between the anchor 10 andthe platform 24 for transmitting rotation of the platform to the anchorwhen the platform is still attached to the anchor as shown in FIGS. 1and 2 and the platform is rotated using a wrench. It is noted that inembodiments that do not include the thread 16 on the anchor 10 (andtherefore need not be rotated to install), the projection 26 may stillbe retained on the platform as a mechanism for receiving an abutment orother crown supporting structure on the platform. Such an abutment has amating recess for the projection so as to fix a relative rotationalposition between the abutment and the anchor and prevent rotation of thedental superstructures. The orientation means also remains useful as amechanism for the provided plural rotational positions between theabutment and the anchor.

When used in its internal attachment implant application, platform 24 isremoved and an abutment 30 shown in FIG. 6, adapted to support a toothreplacement such as a crown 100 in FIG. 14, is placed on the anchor. Theabutment 30 includes a foundation 40 extending into and fixed to theabutment receiving bore 22 in the anchor 10, when the tooth replacementis to be supported on the anchor in its internal attachment applicationin a patient's mouth.

The outer tapered surface 14, e.g. in FIG. 1, and the thread 16, aretextured to improve bone integration to the anchor. This is done in aknow fashion, e.g. by coating the surfaces with a titanium plasma spray.

The upper portion 18 of the anchor 10 has a non-threaded andsubstantially cylindrical neck 19. The neck has an outer surface that istextured to improve bone integration to the anchor. A polishedcylindrical collar 21 which is about 1 to 2 mm tall, is provided on theouter surface of the anchor, above the neck.

The platform has an upper, outer polished surface 27 that is contiguouswith the cylindrical outer surfaces of the collar 21 and neck 19.

The anchor 10 includes one or more circumferentially spaced toe recesses42 at a lower end of the anchor, for improving threading of the anchorto the bone of the jaw. Recess or recesses 42 cause the anchor to beself-threading in the bone as the anchor is rotated.

The implant anchor, in the embodiments of FIGS. 1-8 has a abutmentreceiving bore 22 in the form of a female Morse taper surface. Suchsurfaces having a taper or inclination of about 8° or less, have beenfound to securely fix a mating male Morse taper member due to theinter-frictional effects between the tapered surfaces.

The fixation is so secure that the co-rotation means can simply comprisethe platform having a male Morse taper member 23 for frictionallyengaging the female Morse taper surface of the abutment receiving bore22.

The platform 24 also has a lower surface that closely engages and coversthe upper surface 20 of the anchor 10. A removal slot 44 either in theunder surface of platform 24 as shown in FIG. 2, or on the upper surface20 as shown in FIG. 4, but in any case between the lower surface of theplatform and the upper surface of the anchor is provided for receiving atool such as a small screw driver or like device, to overcome thefrictional engagement of the Morse taper, and remove the platform 24from the anchor 10.

A more positive co-rotation means comprises one or morecircumferentially spaced male keys 46 (FIG. 4) projecting from eitherthe platform or the anchor, and a corresponding female key recess 48 inthe other for receiving the male key projection (FIG. 4). This alsoprovided orientation means between the abutment and the anchor thatpermits an equal number of rotational position for the abutment on theanchor.

A screw bore 50 extends into the platform 24 and a fixing screw 52extending into the screw bore, in the embodiments of FIGS. 2-5 and 7-9.The screw bore in the platform is at least partly threaded in theembodiment of FIG. 5, for holding an abutment such as abutment 60 inFIG. 7, to the platform 24. As shown is FIG. 7, the bore 50 in theplatform can be partially or entirely threaded in order to receivethreads of the screw 52 to fix the abutment 60. In this way, a shorterscrew can be used which need not be threaded all the way into the anchoror the anchor may even be provided with no threaded bore. The same istrue of FIG. 8 where part or all of the central bore through theabutment 62 may be threaded.

FIGS. 5 and 6 also illustrate how the use of multiple, e.g. six, sets ofmale and female keys 46,48, can be equally and circumferentially spacedaround the implant (preferable with the female keys 48 in the topsurface of the implant). In the case of off-axis abutments that areneeded to accommodate implants that are at an angle to the axis of thecrown to be installed (e.g. see FIGS. 6-8 of U.S. Pat. No. 5,417,570 toZuest, et al.) this gives the practitioner an equal number of rotationalpositions to install the off-axis abutment. FIG. 15 shows four male keys46 on the inner perimeter of the Morse taper surface 22 to provide themultiple position possibility for a platform and/or an abutment providedwith four or more mating female key recesses. The inward placement ofthe keys also avoids the presence of an outer margin between theabutment and the anchor that is zig-zagged, since the keys are allspaced inwardly of the outer surface of the anchor. The line betweenthese parts is a continuous circle which is thought to reduce thepossibility of bacterial over growth.

In the embodiments of FIGS. 2-4 and 7-9, the screw bore has a threadedportion 54 that extends into the anchor 10, below the abutment receivingbore 22 for receiving the screw 52 for holding the platform to theanchor and/or for holding the abutment to the anchor, and/or for alsoholding a crown 102 to the abutment and anchor as in the embodiment ofFIG. 13.

The non-circular wrench-engaging projection 26 contains a counter sink29 (see FIG. 2, for example). This accommodates the head of the screw 52in the counter sink. Screw 52 can be turned using a Allen wrench in aninternal hex or other engagement recess in the screw head (FIG. 2), or asocket wrench on an external hex or other engagement surface (FIG. 4).

In its external application, the abutment 60 is attached to the maleMorse taper member 23 of the platform in the embodiment of FIG. 7. Inits internal attachment application, the abutment 62 with its foundation61 having a male Morse taper member for frictionally engaging the femaleMorse taper surface of the abutment receiving bore, can be provided asshown in FIG. 8. FIG. 6 illustrates a similar internal attachmentembodiment but without screw bore or screw.

As shown in FIGS. 9, 11 and 12, the abutment receiving bore 72 may bepolygonal, e.g hexagonal. In these embodiments, the platform 24 includesa polygonal extension 74 extending from the platform, into the abutmentreceiving bore 72. In the embodiment of FIG. 10, a screw bore isprovided through the platform 25, and the bore has a threaded portion 54like that illustrated in FIG. 8, extending into the anchor 10, below theabutment receiving bore 22. The fixing screw 52 extends through theplatform 25 and threads to the anchor 10 for holding the platform to theanchor. In this embodiment the platform is a cylindrical disk engagedonto the upper surface 20 of the anchor 10, with no portion extendinginto the abutment receiving bore 22. The same type of disk shapedplatform 25 can be used with the polygonal bores of the anchors in FIGS.11 and 12. In each male and mating female keys 46 and 48 act as theco-rotation or orientation means.

According to the invention a universal implant arrangement is providedin that the platform with external wrench-engaging projection can beused to seat the anchor, and if left in place acts as the top surface ofthe implant to which other dental superstructures can be externallyattached. If, however, the platform is removed, other dental devicesuperstructures may be internally attached to the anchor. An internalwrench-engaging device can be used either with the polygonal abutmentreceiving bore of FIG. 9, or even with a wrench outfitted with a Morsetaper member. After this seating, a period of four to six months ensuesduring which time osseointegration takes place on the external surfaceof the implant. After this period, the implant upon uncovering (stagetwo surgery) may be left as is and function as an external attachmentimplant. At that time it may also be converted to an internal attachmentimplant by removing the platform and using the internal bore as areceptacle for internal attachment structures.

After the period of integration, when the implant is uncovered (stagetwo surgery), a healing abutment is attached to the implant and softtissue healing takes place. At this point the abutment of the inventionis installed, either as the abutment 62 with its own foundation 61(internal attachment application after platform 24 is removed), or theabutment 60 which uses the parts of the retained platform 24 extendinginto the abutment receiving bore 22 as the foundation (externalattachment application).

The diameter at the top neck 19,21 of the anchor and contiguous platformsurface 27, is about 2-8 mm and preferably 3-7 mm. The length of theimplant from top surface 28 of the platform to the bottom of anchor 10is about 5-18 mm and preferably 6-15 mm. The platform 24 is attached tothe anchor 10 in the usual case when a product embodying the inventionis supplied to a practitioner for use.

While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

1. A dental implant anchor (10) for attaching an abutment with at leastone replacement tooth to the jaw bone of a mammal, the anchorcomprising: a lower portion (12) with an outer tapered surface (14)which has a thread (16) and is textured to improve bone integration tothe anchor; an upper portion (18) with a cylindrical polished collar(21), the upper portion having an upper surface (20) adapted to beengaged by an abutment; the anchor having an abutment receiving bore(22) extending into the anchor and opening at the upper surface of theupper portion for receiving an abutment, and a threaded bore portion(54) extending into the anchor (10) below the abutment receiving bore(22) for receiving a screw; the upper portion (18) of the anchorincluding a cylindrical and non-threaded neck (19) between the polishedcollar (21) and the a lower portion (12), the neck having an outersurface that is textured to improve bone adhesion to the anchor, theouter tapered, threaded and textured surface of the lower portion (12)being axially longer than the axial length of the upper portion (18);and a platform (24) having a portion engaged in the abutment receivingbore (22), the platform having an upper, outer polished surface (27)that is contiguous with the cylindrical outer surface of the collar(21).
 2. The dental implant anchor according to claim 1, including atleast one toe recess (42) on the outer surface of the lower portion ofthe anchor for improving threading of the anchor to the bone of the jaw.3. The dental implant anchor according to claim 1, wherein the abutmentreceiving bore contains a female tapered surface.
 4. The dental implantanchor according to claim 3, wherein the female tapered surface is aMorse taper.
 5. The dental implant anchor according to claim 1, whereinthe abutment receiving bore is polygonal.
 6. The dental implant anchoraccording to claim 1, including a polygonal extension extending from theplatform, into the abutment receiving bore.
 7. The dental implant anchoraccording to claim 1, including a fixing screw (52) extending into thethreaded bore portion (54).
 8. The dental implant anchor according toclaim 1, including an abutment with a foundation for extending into theabutment receiving bore and a screw for holding the abutment to theanchor.
 9. The dental implant anchor according to claim 8, wherein theabutment receiving bore is polygonal.